Installation and method for hydroprocessing or hydroconversion, using tubular heat exchangers provided with inserts

Abstract

The present invention relates to an installation and a method for hydroprocessing or hydroconversion using at least one tubular feed / effluent heat exchanger provided with inserts.

Description

[0001] INSTALLATION AND PROCESS OF HYDROTREADING OR HYDROCOVERY WITH TUBULAR HEAT EXCHANGERS EQUIPPED WITH INSERTS

[0002] technical field

[0003] The present invention relates to the field of hydrotreating (e.g., hydrometallation, hydrodeazotation, and / or hydrodesulfurization of residue or diesel fuel) and hydroconversion (e.g., hydrocracking of heavy feedstocks). In particular, the present invention relates to the use of inserts in tubular heat exchangers implemented in hydrotreating or hydroconversion units.

[0004] Previous technique

[0005] The use of heat exchangers in units for the hydrotreating or hydroconversion of petroleum feedstocks is well-established, particularly for preheating the feedstock mixed with hydrogen before it is sent to a hydrotreating or hydroconversion reactor. Heat exchange typically occurs in the heat exchanger between the feedstock and the hydrotreated / hydroconverted effluent exiting the reactor; such a heat exchanger is commonly referred to in the field as a "feed-to-effluent" heat exchanger.

[0006] In general, a furnace placed downstream of the feed-effluent exchanger, before the entry into the reactor, allows the feed to be brought to the target temperature of the reactor required for carrying out the hydrotreating and / or hydroconversion reactions.

[0007] Patents FR3075941 and FR3075942 refer to such hydrotreatment or hydroconversion processes in which feed-effluent heat exchangers are used, and in particular relate to special feed-effluent heat exchangers, known as wound heat exchangers, comprising several bundles of tubes wound helically around a central core, in many superimposed layers, which provide gains in efficiency and operating costs compared to conventional shell-and-tube heat exchangers, but which nevertheless constitute complex and expensive equipment to manufacture.

[0008] Conventional shell-and-tube heat exchangers have a long history. Patents US2978226, EP1113238, and EP2975353 describe examples of this type of heat exchanger. Well-known shell-and-tube heat exchangers include BEU and DEU standard heat exchangers, which consist of U-tube bundles. Other examples of shell-and-tube heat exchangers are found in the oil refining industry, such as AES tubular heat exchangers with tubes through which the fluid flows in a single pass. Tubular heat exchangers (i.e.Heat exchangers (including tube-type heat exchangers, for example, shell-and-tube heat exchangers) of the feed-to-effluent type used in hydrotreatment or hydroconversion processes are characterized by being two-phase heat exchangers, meaning that the fluid on the tube side comprises two phases, typically liquid and gas. Any increase in pressure drop is often critical for the operation of this type of heat exchanger, compared to single-phase heat exchangers (i.e., the fluid on the tube side comprises only one phase, typically liquid).Not only are pressure losses generally higher in the case of two-phase heat exchangers compared to single-phase ones, but these feed-to-effluent heat exchangers in hydrotreating and / or hydroconversion processes operate at high pressure, and the hydrogen compressor(s) used in these processes are expensive pieces of equipment, designed to operate at a given target pressure drop that must be maintained by the feed-to-effluent heat exchanger. The variation around this target pressure drop value, in particular the excess pressure drop, which can also be called additional pressure drop or extra pressure drop, must be minimal, typically less than 10 mbar / m (1.0 x 10⁻¹¹). -4 MPa / m) or even less. The pressure drop constraint is therefore particularly critical for tubular heat exchangers of the feed-effluent type used in hydrotreatment or hydroconversion processes.

[0009] Furthermore, it is generally known to use heat exchanger insert technologies to improve heat transfer efficiency and reduce fouling of industrial heat exchanger tubes. These inserts can be static or moving, typically rotating, within the tubes, can have various shapes, for example, a rigid wire winding, a twisted band, or a central shaft with blades, and can be attached to the tube in different ways, for example, at one end or both ends.

[0010] Fouling due to deposits in heat exchangers can affect many areas, such as oil refining, petrochemicals, and other areas of chemistry, food processing, and energy.

[0011] These deposits can originate from impurities present in liquid streams from various processes, and / or from the decomposition or formation of organic products such as polymers or hydrocarbons and mineral products within said liquid streams. They may consist of suspended impurities that accumulate, deposits of mineral salts dissolved in the liquid streams, coke formation, or sulfur compounds soluble in hydrocarbon streams. These deposits can be generated by excessive fluid temperatures or result from corrosion. These deposits, which gradually accumulate on the walls of heat exchanger tubes over time, impair the performance of the heat exchangers, causing them to lose efficiency over time.The deposits form a solid substance with low thermal conductivity which has the effect of insulating the walls and reducing heat transfer in the exchanger, ultimately damaging the energy efficiency of the industrial processing or manufacturing unit in question implementing the heat exchanger.

[0012] Another consequence of the formation of these deposits on the internal walls of heat exchanger tubes can be reduced flow rates, which are detrimental to the proper functioning of the downstream process, and / or hot spots on the tube's internal surface. These restrictions and / or hot spots can lead to deterioration of the tube structure and thus cause product leaks that can be hazardous to the operator and / or equipment. Fouling of the tubes in a feed-to-effluent heat exchanger can also lead to increased fuel consumption in the furnace located downstream of the heat exchanger in hydrotreating or hydroconversion units for hydrocarbon feedstocks.

[0013] In the field of oil refining in particular, there are many units using heat exchangers that are susceptible to fouling.

[0014] One example is the refining of crude oil, which involves preheating the crude oil with the hot atmospheric residue exiting an atmospheric distillation unit. Many so-called heavy crude oils are very rich in asphaltenic compounds that can form sediments, as well as in sulfur and other corrosive compounds that are prone to depositing on the internal walls of the heat exchanger tubes through which they circulate.

[0015] The integration of inserts into heat exchanger tubes during crude oil preheating to improve heat transfer and reduce fouling is well-known, and for example, described in French patent FR2569829. This patent covers a rotary insert with a rigid, solenoid-shaped metal winding that is rotated by the fluid flowing through the tube. However, since this involves preheating crude oil that is subsequently sent to an atmospheric distillation unit, the pressure conditions (atmospheric pressure) do not pose a constraint for the heat exchangers used for preheating, which are also single-phase exchangers and therefore less constrained in terms of pressure drop.

[0016] Another common problem in hydrotreating and hydroconversion processes is catalyst deactivation, and the strategies implemented to optimize catalyst use in the process. In hydrotreating and hydroconversion processes, a catalyst is typically used that deactivates over time, primarily due to catalyst poisoning from metals in the feedstock or from coke forming in the reactors. To counteract this catalyst deactivation, the reactor temperature is generally increased during the lifetime of the hydrotreating / hydroconversion unit to maintain process performance.This allows, in particular, for an increase in cycle time related to the catalyst's lifespan in the reactor, thereby limiting the frequency of replacing the spent catalyst with fresh catalyst and / or the amount of fresh catalyst used as a top-up, and the associated costs. However, in some cases, achieving the desired temperature levels can be difficult due to the technical limitations of the equipment used to heat the feedstock, such as furnaces and heat exchangers.

[0017] Another problem facing manufacturers is that hydrotreatment or hydroconversion units must be able to process loads that can vary over time, and in particular loads that may have a different fouling power.

[0018] In general, the refining and petrochemical industries are increasingly actively seeking solutions to reduce their energy bills and CO2 emissions. Improving the energy efficiency of heat exchangers is a promising avenue for achieving these goals.

[0019] The present invention falls within this context, and relates to the use of inserts in feed-effluent type tube heat exchangers for hydrotreatment and / or hydroconversion processes of hydrocarbon feedstocks.

[0020] Objectives and Summary of the Invention

[0021] The present invention aims to overcome, at least in part, the prior art problems described above, and in particular aims to provide a hydrotreatment and / or hydroconversion plant for hydrocarbon feedstocks incorporating at least one tubular feed / effluent heat exchanger, and the associated process, meeting one or more of the following objectives:

[0022] - reduce CO2 emissions from the process, in particular from a hydrotreating process of middle distillates (diesel) which follows a so-called "cold" scheme as defined later in the description;

[0023] - increase the processing capacity of the installation / process;

[0024] - lower capital expenditure (CAPEX) on heat exchangers with the possibility of using smaller heat exchangers for a given treatment capacity of the installation / process;

[0025] - to provide operational flexibility of the installation and the process in case of variation of the load treated, particularly in terms of fouling power.

[0026] Thus, to achieve at least one of the aforementioned objectives, among others, the present invention proposes, according to a first aspect, a hydroconversion or hydrotreatment installation for a hydrocarbon feedstock, comprising:

[0027] - at least one tubular feed-effluent heat exchanger configured to: preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a charging furnace of a hydrotreating or hydroconversion reaction section, and cool a reaction effluent from the hydrotreating or hydroconversion reaction section, said tubular feed-effluent heat exchanger comprising a plurality of tubes through which the reaction effluent passes, said tubes comprising an insert; - the charging furnace configured to heat and send the preheated hydrocarbon feed-hydrogen stream mixture to the hydrotreating or hydroconversion reaction section;

[0028] - the hydrotreating or hydroconversion reaction section configured to hydrotreat or hydroconvert the hydrocarbon feedstock and produce the reaction effluent;

[0029] - a first air-cooled condenser configured to cool at least part of the reaction effluent cooled by said tubular charge-effluent heat exchanger before it is sent into a high-pressure cold separator vessel;

[0030] - the high-pressure cold separator vessel configured to separate at least a portion of the cooled reaction effluent into a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen, and

[0031] - a separation column configured to separate said first liquid effluent comprising at least a light fraction into a background liquid and a head effluent.

[0032] According to one or more embodiments of the invention, the installation further comprises a medium-pressure cold separator vessel configured to separate the first liquid effluent comprising at least a light fraction into a second liquid effluent comprising at least a light fraction sent to the separation column (and a second gaseous effluent comprising hydrogen).

[0033] According to one or more embodiments of the invention, the installation further comprises:

[0034] - a first heat exchanger configured to pre-cool all of the reaction effluent before it is sent to said tubular charge-effluent heat exchanger;

[0035] - a second heat exchanger configured to cool the bottom liquid from the separation column, and to heat and send the second liquid effluent from the medium-pressure cold separator tank to the separation column after additional heating in said first heat exchanger.

[0036] According to one or more embodiments of the invention, the installation further comprises:

[0037] - a high-pressure hot separator vessel configured to separate the cooled reaction effluent from said tubular charge-effluent heat exchanger into a first liquid effluent comprising at least a heavy fraction and a first gaseous effluent comprising a light fraction sent to the high-pressure cold separator vessel after cooling in an external flow heat exchanger and passing through said first air condenser;

[0038] - a medium-pressure hot separator vessel configured to separate the first liquid effluent, comprising at least a heavy fraction, into a second liquid effluent, comprising at least a heavy fraction, sent to the separation column, and a second gaseous effluent, comprising a light fraction, sent to said medium-pressure cold separator vessel after cooling in a second air-cooled condenser. According to one or more embodiments of the invention, the tubular feed-effluent heat exchanger is provided with a plurality of inserts fixed to the tubes of said feed-effluent heat exchanger, each insert comprising an element having a rigid helical winding of a metal rod comprising several turns, preferably the element comprising:

[0039] - a sequence of several successive sections of length L1 comprising a rigid helical winding of a metal rod with several turns and a second section of length L2 comprising a straight metal rod, and

[0040] - a first end connected to a system for fixing said element to an inlet of said tube.

[0041] According to one or more embodiments of the invention, the insert element is rotationally mobile, said first end of the element being attached to a mechanical link of the fixing system, said mechanical link allowing free rotation of said element about itself around the axis (Z) of said tube under the action of the reaction effluent passing through said tube, and said rotationally mobile element having a second free end opposite said first end.

[0042] According to one or more embodiments of the invention, the rotating moving element of the insert further comprises a rotating drive piece positioned between the first end of said element and connected to the first section of the sequence positioned first in the sequence, said rotating drive piece comprising a shaft coaxial with the helical winding of the first section and provided with at least two blades attached to said shaft.

[0043] According to one or more embodiments of the invention, the insert comprises:

[0044] - a pitch pl of the helical winding of the first section between 10 mm and 50 mm;

[0045] - a length L1 of the first section and a length L2 of the second section between 50 mm and 12,000 mm;

[0046] - a total length of the insert Li between 50% and 100% of the total length L tof the heat exchanger tube (charge-effluent), the total length of the tube L t being between 500 mm and 6000 mm.

[0047] According to a second aspect, the present invention relates to a process for the hydroconversion or hydrotreatment of a hydrocarbon feedstock, comprising the following steps:

[0048] - preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a charging furnace by means of at least one tubular feed-effluent heat exchanger comprising a plurality of tubes through which a reaction effluent passes and comprising an insert in at least one of said tubes;

[0049] - heat and send the preheated hydrocarbon feed-hydrogen stream mixture to a hydrotreating or hydroconversion reaction section using the feed furnace;

[0050] - hydrotreat or hydroconvert the hydrocarbon feed in the hydrotreating or hydroconversion reaction section comprising at least one reactor comprising at least one catalyst comprising at least one element selected from the elements of Group VIII of the periodic table to form the reaction effluent;

[0051] - to cool the reaction effluent from the hydrotreatment or hydroconversion reaction section by means of said tubular charge-effluent heat exchanger;

[0052] - lower the temperature of at least part of the reaction effluent from the tubular charge-effluent heat exchanger by means of a first air condenser before sending it into a high-pressure cold separator vessel;

[0053] - to separate said at least a portion of the cooled reaction effluent from the first air-cooled condenser in the high-pressure cold separator vessel to form a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen; and

[0054] - separate the first liquid effluent comprising at least a light fraction in a separation column to form at least a bottom liquid and a top effluent.

[0055] According to one or more embodiments of the invention, the tubular feed-outlet heat exchanger is provided with a plurality of inserts fixed to the tubes of said tubular feed-outlet heat exchanger, each insert comprising an element having a rigid helical winding of a rod comprising several turns, preferably the element comprising:

[0056] - a sequence of several successive sections of length L1 comprising a rigid helical winding of a rod with several turns and a second section of length L2 comprising a straight rod, and

[0057] - a first end connected to a system for fixing said element to an inlet of said tube.

[0058] According to one or more embodiments of the invention, the hydrotreating or hydroconversion of the hydrocarbon feedstock is carried out with at least one of the following operating conditions:

[0059] - the temperature is between approximately 200°C and approximately 550°C;

[0060] - the total pressure is between approximately 1 MPa and approximately 38 MPa;

[0061] - the overall hourly spatial velocity of the liquid charge is between approximately 0.05 h 1 and about 12 hours 1

[0062] - the hydrogen flow comprises between approximately 50% and approximately 100% of the volume of hydrogen relative to the volume of the hydrogen flow;

[0063] - the quantity of hydrogen relative to the liquid hydrocarbon charge is between approximately 50 Nm 3 / m 3 and approximately 5000 Nm 3 / m 3

[0064] According to one or more embodiments of the invention, the hydrocarbon filler is chosen from:

[0065] - feedstocks of fossil origin selected from diesel fuels, vacuum distillates, atmospheric residues, vacuum residues or Fischer-Tropsch unit effluents, - feedstocks from biomass conversion selected from vegetable, algal, fish, used food oils, fats of vegetable or animal origin, or oils produced from lignocellulosic biomass,

[0066] - feedstocks derived from the conversion of waste materials selected from pyrolysis oils of plastics, tires, or solid recovered fuels,

[0067] - and their mixtures.

[0068] According to one or more embodiments of the invention, the high-pressure cold separator vessel (B-2) is operated at a pressure lower than the pressure of the hydrotreating or hydroconversion reaction section (Rl) and / or in which the temperature of the high-pressure cold separator vessel (B-2) is between 20°C and 100°C.

[0069] According to one or more implementations of the invention, the process further comprises the following steps:

[0070] - pre-cool the entire reaction effluent from the hydrotreatment or hydroconversion reaction section (Rl) by means of a first heat exchanger (El) before sending it to the tubular feed-effluent heat exchanger (E-2);

[0071] - separate said first liquid effluent comprising at least a light fraction from the high-pressure cold separator flask (B-2) into a medium-pressure cold separator flask (B-4) to form a second liquid effluent comprising at least a light fraction sent to the separation column (Cl) and a second gaseous effluent comprising hydrogen;

[0072] - cool the bottom liquid from the separation column (Cl) and heat and send to said separation column (Cl) said second liquid effluent comprising at least a light fraction by means of a second heat exchanger (E-4);

[0073] - heat said second liquid effluent comprising at least a light fraction from second heat exchanger (E-4) before sending it to said separation column (Cl) by means of said first heat exchanger (El).

[0074] Other objects and advantages of the invention will become apparent from the following description of particular embodiments of the invention, given by way of non-limiting examples, the description being made with reference to the attached figures described below.

[0075] List of figures

[0076] Figure 1 is a general diagram of an installation for implementing a hydroconversion or hydrotreating process according to the present invention, in which the hydrocarbon feedstock in the reaction section is preheated by the reaction effluent in at least one tubular heat exchanger incorporating at least one insert, and then heated in a furnace before entering the reaction section. Figure 2, derived from the general diagram in Figure 1, corresponds to a diagram of an installation for implementing a hydroconversion or hydrotreating process according to a first embodiment of the invention, following a so-called "cold" diagram.

[0077] Figure 3, derived from the general diagram of Figure 1, corresponds to a diagram of an installation for the implementation of a hydroconversion or hydrotreatment process according to a second embodiment of the invention following a so-called "hot" diagram.

[0078] Figure 4 represents an insert and its method of attachment to the tube of a single-phase heat exchanger, known from the prior art.

[0079] Figure 5 is a three-dimensional (3D) schematic view of an example of an insert integrated into a tubular charge-effluent heat exchanger of an installation according to the invention.

[0080] Figure 6 shows the same insert as illustrated in Figure 5, also showing a portion of a heat exchanger tube and a system for attaching the insert to the tube.

[0081] Figure 7 shows a rear view of a portion of the insert and heat exchanger tube illustrated in Figures 6 and 7.

[0082] Figure 8 is a schematic 3D view of another example of an insert integrated into a tubular charge-effluent heat exchanger of an installation according to the invention.

[0083] In the figures, the same references designate identical or analogous elements.

[0084] Description of the implementation methods

[0085] Terminology

[0086] In this description, the term "include" is synonymous with (means the same as) "comprise," "include," and "contain," thus being inclusive or open-ended and not excluding other elements not mentioned. It is understood that the term "include" includes the exclusive and closed term "consist."

[0087] In this description, the expression "between ... and ..." means that the limit values ​​of the interval are included in the range of values ​​described, unless otherwise specified.

[0088] Furthermore, in this description, the terms "essentially," "substantially," or "approximately" relative to a reference value correspond to an approximation of ±10%, ±5%, preferably ±1%, and most preferably ±0.5%. This may be a value of temperature, pressure, distance, speed, flow rate, compound content, etc.

[0089] In this description, the various parameter ranges characterizing a given device, or relating to a step in a process implementing said device, such as ranges relating to dimensions (lengths, diameters, etc.), angles, pressure ranges, or temperature ranges, may be used alone or in combination. For example, in the context of the present invention, a preferred range of pressure values ​​may be combined with a more preferred range of temperature values.

[0090] According to the present invention, pressures are absolute pressures, also noted as abs., and are given in absolute MPa (or abs. MPa), unless otherwise indicated.

[0091] In this description, the term "hydroconversion" refers to a process whose primary purpose is to reduce the boiling point range of a hydrocarbon feedstock, and in which a substantial portion of the feedstock is converted into products with lower boiling point ranges than the original feedstock. Hydroconversion generally involves the fragmentation of larger hydrocarbon molecules into smaller molecular fragments with fewer carbon atoms and a higher hydrogen-to-carbon ratio. The reactions carried out during hydroconversion reduce the size of hydrocarbon molecules, primarily by breaking carbon-carbon bonds, in the presence of hydrogen to saturate the broken bonds and aromatic rings.The mechanism by which hydroconversion occurs typically involves the formation of hydrocarbon free radicals during fragmentation, primarily through thermal cracking, followed by the capping of the free radical terminations or fragments with hydrogen in the presence of active catalyst sites. Of course, during a hydroconversion process, other reactions typically associated with hydrotreating may occur, such as, among others, the removal of sulfur or nitrogen from the feedstock, or olefin saturation, as more broadly defined below.

[0092] The term "hydrotreating," commonly referred to as "HDT," describes a gentler process than hydroconversion. Its primary purpose is to remove impurities such as sulfur, nitrogen, oxygen, halides, and trace metals from the feedstock, and to saturate olefins and / or stabilize hydrocarbon free radicals by causing them to react with hydrogen rather than allowing them to react with themselves. The main objective is not to alter the feedstock's boiling point range. Thus, hydrotreating includes hydrodesulfurization reactions (commonly called "HDS"), hydrodeazotation reactions (commonly called "HDN") and hydrodemetallation reactions (commonly called "HDM"), accompanied by hydrogenation, hydrodeoxygenation, hydrodearomatization, hydroisomerization, hydrodealkylation, hydrocracking, hydrodeasphalting and Conradson carbon reduction reactions.Hydrotreating is most often implemented using a fixed bed reactor, although other reactors can also be used for hydrotreating, for example a bubbling bed hydrotreating reactor.

[0093] In this description, a hydroconversion or hydrotreating catalyst is defined as a porous supported catalyst used in a hydroconversion or hydrotreating process of a hydrocarbon feedstock. In the remainder of this description, the term "catalyst" refers to such a hydroconversion or hydrotreating catalyst, unless otherwise specified. Such catalysts typically comprise (i) a catalyst support with a large surface area and numerous interconnected channels or pores, and (ii) an active phase in the form of fine particles of an active catalyst such as cobalt, nickel, tungsten, molybdenum sulfides, or mixed sulfides of these elements (e.g., NiMo, CoMo, etc.), dispersed within the pores. Supported catalysts are commonly produced as cylindrical extrudates ("pellets") or spherical solids, although other shapes are possible.Such a catalyst is detailed further in the description.

[0094] In this description, chemical element groups may be given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC Press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII (or VII IB) according to the CAS classification corresponds to the metals in columns 8, 9, and 10 according to the new IUPAC classification, and group Vlb according to the CAS classification corresponds to the metals in column 6 according to the new IUPAC classification.

[0095] In this description, when mentioned, the positions "front", "rear", "horizontal", "vertical", etc. of the various elements of the insert and the heat exchanger tube are defined in relation to a tubular heat exchanger in the operating position and in relation to the direction of flow of the fluid passing through the heat exchanger tube.

[0096] In this description, the fluid flow velocity in the tube refers to the surface velocity of the fluid flowing through the tube, V_SF, commonly understood as the ratio between the volumetric flow rate of the fluid Q and the internal cross-sectional area of ​​the tube S: V_SF = Q / S. The same applies to the threshold speed for rotation of an insert, which is a surface velocity, more precisely a specific value of V_SF unique to the insert used.

[0097] In this description, "rigid" refers to the helical winding of a rod, preferably metallic, meaning a winding that does not deform, or hardly deforms, irreversibly under the action of the fluid that rotates the moving part containing said winding, under normal operating conditions of the heat exchanger tubes. In particular, said winding does not deform, or hardly deforms, irreversibly when the circulating fluid exhibits variations in speed, viscosity, and / or temperature.

[0098] In this description, a tube-side heat exchanger, or tubular heat exchanger, is defined as a heat exchanger comprising at least one tube inside which flows a fluid commonly referred to as the "tube-side fluid," exchanging heat with a fluid flowing outside said tube. The heat exchangers referred to in this invention are classically known as shell-and-tube heat exchangers with straight (straight) tubes, in which the tube-side fluid flows inside a set of parallel tubes called a tube bundle. These tubes are enclosed in a shell called a shell. The other fluid, called the "shell-side fluid," flows inside the shell but outside the tubes. The flow of the fluids on the tube and shell sides can be co-current and / or counter-current. The tubes are often long, typically up to 6 m, and of small diameter to optimize the surface area to volume ratio.They are generally held at their ends in perforated plates called tube sheets, which serve to support the tubes and also to separate the fluids, and may be supported between the tube sheets by intermediate support plates (perforated plates transverse to the tubes). The tubes can also be U-shaped, and their ends may, for example, be attached to a single tube sheet. Shell and tube heat exchangers can be single-pass or multi-pass, for example, two-pass (the fluid on the tube side flows through the tubes in one direction, then returns in the opposite direction thanks to an internal configuration (such as a partition in a plenum, or via a U-shaped tube configuration)).

[0099] According to the present invention, tubular heat exchangers are not wound heat exchangers, that is to say, comprising one or more bundles of tubes wound helically around a central core, in many superimposed layers.

[0100] In this description, a heat exchanger, such as the feed-effluent heat exchanger, is understood as operating only with fluids from the process, typically effluents produced in the process steps, unlike external flow heat exchangers, understood as heat exchangers in which one of the fluids involved in heat transfer is external to the process, for example, water vapor external to the process.

[0101] In this description, the pitch of a helical winding with multiple turns is understood by the commonly accepted definition, which is the distance measured between the centers of two turns. In a two-dimensional representation, it is the distance between two crests on the same side of the winding axis, and in a 3D representation, it is the length (distance) between two turns around the axis of revolution of the turn (or the distance traveled along the axis of revolution of the turn to make one complete turn).

[0102] Embedding methods for the installation and implementation of the process are described in detail below. Numerous specific details are presented to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the installation and process can be implemented without necessarily including all of these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0103] In this description, the various embodiments presented can be implemented separately or in combination with one another, without limitation as to the number of combinations where technically feasible. The present invention relates to an installation and a method for the hydrotreating or hydroconversion of a hydrocarbon feedstock, such as installations and methods for the hydroconversion of heavy feedstocks, for example, residues or vacuum gas oil. The present invention also relates to an installation and a method for hydrotreating, such as installations and methods for the hydrometallation, hydrodeazotation, and / or hydrodesulfurization of residues or gas oil.

[0104] The present invention thus proposes an installation and a method for hydrotreating or hydroconverting a hydrocarbon feed comprising at least one tubular feed-effluent heat exchanger (E-2) equipped with inserts.

[0105] Hydrotreatment or hydroconversion installation / process

[0106] Reference is first made below to figures 1 to 3 to describe the installation and the hydrotreatment or hydroconversion process according to the invention.

[0107] Reference will be made below to figures 5 to 8 to describe examples of inserts, which are not exhaustive, that are integrated into the E-2 tubular charge-effluent heat exchanger of the installation.

[0108] According to the invention, inserts can also be used in other heat exchangers than the tubular charge-effluent heat exchanger E-2 within the installation, such as the known insert illustrated in Figure 4, or the same types of inserts as those used in the tubular charge-effluent heat exchanger E-2 and illustrated in the other Figures 5-8.

[0109] The hydrotreatment or hydroconversion installation according to the invention includes at least one tubular feed-effluent heat exchanger E-2 configured to preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a feed furnace Fl of a hydrotreatment or hydroconversion reaction section Rl, and to cool a reaction effluent from the hydrotreatment or hydroconversion reaction section Rl.

[0110] The tubular feed-effluent heat exchanger E-2 comprises a plurality of tubes 10 through which a fluid, in this case the reaction effluent, flows, and includes an insert in at least one of said tubes, preferably fixed to the upstream end of at least one of said tubes. In this description, upstream and downstream refer to the direction of fluid flow. The tubular feed-effluent heat exchanger E-2 is a two-phase heat exchanger, that is, configured for the circulation of a gas phase and a liquid phase within said tubes.

[0111] In the E-2 tubular feed-effluent heat exchanger, the two fluids, tube-side and shell-side, are two-phase. The fluid on the tube side of the E-2 heat exchanger comprises a gas phase and a liquid phase: the reaction effluent passing through the tubes includes a liquid phase and a vapor phase containing, in particular, H2, NH3, H2S, and some of the vaporized products. The hydrocarbon feed-hydrogen flow mixture to be heated, circulating on the shell-side, therefore also comprises a gas phase, e.g., gaseous hydrogen, and a liquid phase, e.g., the hydrocarbon feed. The installation according to the invention further comprises:

[0112] - the charging furnace Fl configured to heat and send the preheated hydrocarbon charge-hydrogen flux mixture to the hydrotreating or hydroconversion reaction section Rl;

[0113] - the hydrotreating or hydroconversion reaction section Rl configured to hydrotreat or hydroconvert the hydrocarbon feedstock and produce the reaction effluent;

[0114] - a high-pressure cold separator vessel B-2 configured to separate at least a portion of the cooled reaction effluent into a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen; and

[0115] - a separation column Cl configured to separate said first liquid effluent into at least a bottom liquid and a top effluent.

[0116] With reference to Figure 1, a hydrotreatment or hydroconversion plant according to the invention for hydrocarbon feedstocks, such as hydrocarbon feedstocks of fossil origin or from the conversion of biomass or waste, taken alone or in mixtures, comprises:

[0117] - at least one tubular feed-effluent heat exchanger E-2, typically of shell-and-tube type, for example one or more tubular feed-effluent heat exchanger trains E-2, configured to preheat a mixture of the hydrocarbon feed (line 1) with a hydrogen stream (line 4), hereafter referred to as the hydrocarbon feed-hydrogen stream mixture (line 5), with the reaction effluent (line 8), possibly pre-cooled in an optional heat exchanger El (line 9), from a hydrotreating or hydroconversion reaction section Rl;

[0118] - a charging furnace Fl configured to heat the preheated hydrocarbon feed-hydrogen stream mixture (line 6) from the tubular feed-effluent heat exchanger E-2 and send the heated hydrocarbon feed-hydrogen stream mixture (line 7) to the hydrotreating or hydroconversion reaction section Rl;

[0119] - the hydrotreating or hydroconversion reaction section Rl;

[0120] - optionally a first heat exchanger El configured to pre-cool all of the reaction effluent (line 8) before sending it into said tubular charge-effluent heat exchanger E-2;

[0121] - optionally a high-pressure hot separator vessel Bl, the charge of which consists of the reaction effluent cooled after passing through the tubular charge-effluent heat exchanger or heat exchanger(s) train(s) E-2 (line 10), configured to separate a first liquid effluent comprising at least a heavy fraction (line 17) and a first gaseous effluent comprising a light fraction (line 11), said first gaseous effluent comprising a light fraction being sent to the high-pressure cold separator vessel (B-2) after cooling in an external flow heat exchanger (E-3), possible addition of water (line 13) to limit the risks of ammonium salt deposits and therefore corrosion, and passage through a first air condenser (Al);- a high-pressure cold separator vessel B-2, the charge of which includes at least a part of the reaction effluent from the hydrotreating or hydroconversion reaction section Rl and cooled at least after passing through the tubular charge-effluent heat exchanger or heat exchanger(s) train(s) E-2 (lines 10, 11, 12 and 14), configured to separate a first liquid effluent comprising at least a light fraction (line 20) and a first gaseous effluent comprising hydrogen (line 15);

[0122] - optionally an external flow heat exchanger E-3 configured to cool at least part of the reaction effluent (or optionally the first gaseous effluent including a light fraction from the hot high-pressure separator vessel Bl);

[0123] - the first air condenser Al to lower the temperature of at least part of the reaction effluent cooled by the tubular charge-effluent heat exchanger E-2 before it is sent to the high-pressure cold separator vessel B-2 (or optionally to condense the first gaseous effluent including a light fraction from the high-pressure hot separator vessel Bl and optionally also from the second heat exchanger E-3);

[0124] - optionally a medium-pressure hot separator B-3, the charge of which is the first liquid effluent comprising at least a heavy fraction (line 17) from the high-pressure hot separator Bl, and configured to separate said first liquid effluent comprising a heavy fraction into a second liquid effluent comprising at least a heavy fraction (line 21) which is sent to a separation column Cl, and a second gaseous effluent comprising a light fraction (line 18) sent to a medium-pressure cold separator (B-4) after possible cooling in a second air-cooled condenser A-2;

[0125] - optionally the second air condenser A-2 configured to condense the second gaseous effluent including a light fraction (line 18) from the medium pressure hot separator vessel B-3 and form a second gaseous effluent including a condensed light fraction (line 19);

[0126] - optionally a medium-pressure cold separator B-4, configured to separate the first liquid effluent comprising at least a light fraction (line 20) from the high-pressure cold separator B-2 (and optionally the second gaseous effluent comprising a light fraction (line 18) from the medium-pressure hot separator B-3 (and optionally condensed (line 19) in the second air-cooled condenser A-2)), into a second liquid effluent comprising at least a light fraction (lines 22 and 24) sent to the separation column Cl, and a second gaseous effluent comprising hydrogen which is subtracted from said swab;

[0127] - optionally a second heat exchanger E-4 configured to heat the feed to the separation column Cl, more specifically configured to heat and send the second liquid effluent, including at least a light fraction, from the medium-pressure cold separator vessel B-4 to the separation column Cl after possible additional heating in the first heat exchanger El (line 22, line 23, and line 24), and to cool the bottom liquid from the separation column Cl; - the separation column Cl (egconventional fractionation column or stripping column using a fluid added by line 25) to form a bottom liquid (line 26) and a top effluent (line 28) from the liquid effluent (line 20) from the high-pressure cold separator tank B-2, optionally from the high-pressure hot separator tank Bl (line 17), optionally from the medium-pressure hot separator tank B-3 (line 21), optionally from the medium-pressure cold separator tank B-4 (line 22);.

[0128] - optionally a second furnace (not shown) adapted to heat the bottom liquid of the separation column (e.g. after passing through the second heat exchanger E-4) and distribute it to a fractionation column (not shown);

[0129] - optionally a third heat exchanger (not shown) suitable for cooling or heating the first or second liquid effluent comprising at least a heavy fraction.

[0130] - optionally a third air condenser A-3 to condense the head effluent (line 28) from the separation column Cl and form a condensed head effluent (line 29);

[0131] - optionally a B-5 reflux flask to separate the overhead effluent or condensed overhead effluent into a overhead gaseous fraction (e.g. acid gas) (line 31) and a hydrocarbon liquid cut (e.g. naphtha) (line 30);

[0132] - optionally an amine scrubbing column C-2 allowing to remove at least part of the H2S from the first gaseous effluent containing hydrogen (line 15) from the high pressure cold separator tank B-2, also called recycled hydrogen;

[0133] - optionally a first compression section Kl of recycled and amine-washed hydrogen (line 16);

[0134] - optionally a second K-2 booster hydrogen compression section (line 2) forming compressed booster hydrogen (line 3) which can be mixed with the recycled, washed and compressed hydrogen from the first Kl compression section.

[0135] The E-2 tubular feed-effluent heat exchanger is arranged to heat the hydrocarbon feed-hydrogen flux mixture with the reaction effluent.

[0136] The hydrocarbon load targeted by hydrotreatment and / or hydroconversion can be of a different nature.

[0137] The feedstock can be of fossil origin or derived from the conversion of biomass or waste, either alone or in mixtures. The feedstocks that are treated, and in particular those mentioned below, generally contain heteroatoms such as sulfur, oxygen, and nitrogen, and may contain other contaminants such as iron, titanium, silicon, calcium, sodium, potassium, chlorine, and arsenic, but also, especially for heavier feedstocks, nickel and vanadium.

[0138] The fossil fuel feedstock can include, in particular, a fraction derived from coal or hydrocarbons produced from natural gas, possibly in mixtures. It can also consist of heavy petroleum or synthetic fractions, for example, kerosene, diesel, or distillates obtained through atmospheric and vacuum distillation to produce usable kerosene, diesel, or vacuum distillate. This usable distillate is then either stored in a pool receiving similar products or sent to a downstream unit such as a catalytic cracking unit, where the feedstocks are cracked to produce shorter-chain hydrocarbons. Hydrotreating is often a preliminary step in the treatment of a feedstock using a hydroconversion / hydrocracking process.

[0139] The fossil fuel feedstocks used in a hydrotreating process, in more detail, are for example gasoline, diesel, vacuum diesel, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, feedstocks from thermal or catalytic conversion processes, taken alone or in mixtures.

[0140] The feedstock resulting from biomass conversion may advantageously be selected from vegetable oils, algae or seaweed oils, fish oils, used cooking oils, and fats of vegetable or animal origin; or mixtures of such feedstocks. Said vegetable oils may advantageously be crude or refined, wholly or partially, and derived from plants selected from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor, cottonseed, peanut, linseed, and crambe oils, and all oils derived, for example, from sunflower or rapeseed by genetic modification or hybridization, this list not being exhaustive. Said animal fats are advantageously selected from lard and fats composed of residues from the food industry or from the catering industry.Frying oils, various animal oils such as fish oil, tallow, and lard can also be used. The feedstock from biomass conversion can also advantageously be chosen from among fatty acid methyl esters of vegetable and / or animal origin, or from fatty acid methyl esters of used edible vegetable oils.

[0141] The feedstock resulting from biomass conversion can also be selected from feedstocks produced by thermal or catalytic biomass conversion processes, such as oils derived from biomass, particularly lignocellulosic biomass, using various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, including plants, animals, and their byproducts. "Lignocellulosic biomass" refers to biomass derived from plants or their byproducts. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0142] The feedstock from biomass conversion can also be advantageously chosen from feedstocks from the paper industry. The feedstock from waste conversion can be pyrolysis oil derived from plastics, tires, or solid recovered fuels (SRF). These oils are obtained through thermal or catalytic pyrolysis, or can be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0143] According to one or more embodiments, the hydrocarbon filler is chosen from:

[0144] - feedstocks of fossil origin selected from diesel fuels, vacuum distillates, atmospheric residues, vacuum residues or Fischer-Tropsch unit effluents,

[0145] - feedstocks derived from biomass conversion chosen from vegetable, algal, fish, or used food oils, fats of vegetable or animal origin, or oils produced from lignocellulosic biomass,

[0146] - feedstocks derived from the conversion of waste selected from pyrolysis oils of plastics, tires or RDF,

[0147] - and their mixtures.

[0148] According to one or more embodiments, the initial boiling point of the hydrocarbon feedstock is greater than 120°C.

[0149] In the case of diesel, the initial distillation temperature is generally around 150°C, and the distillation range is typically between 170°C and 390°C. For atmospheric residue, the initial distillation temperature is typically above 300°C, preferably between 340°C and 380°C. For vacuum residue, the initial distillation temperature is typically between 450°C and 600°C, preferably between 500°C and 550°C. Light vacuum gas oil (LVGO) is characterized by a distillation range between 300°C and 430°C, preferably between 340°C and 400°C. Heavy vacuum gas oil (HVGO) is characterized by a distillation range between 400°C and 620°C, preferably between 440°C and 550°C. The usable feedstocks therefore fall within a wide range of boiling points.

[0150] According to one or more embodiments, the hydrocarbon charge contains at least 10% by volume, generally at least 20% by volume, preferably at least 30% by volume, and often at least 40% by volume, or even at least 80% by volume of compounds boiling above 340°C.

[0151] According to one or more embodiments, the nitrogen content of the hydrocarbon load is greater than 500 ppm by weight, generally between 500 ppm and 10000 ppm by weight, more generally between 700 ppm and 4500 ppm by weight and even more generally between 800 ppm and 4500 ppm by weight.

[0152] In one or more embodiments, the sulfur content of the hydrocarbon feedstock is between 0.01 and 5% by weight, generally between 0.2 and 4% by weight, and even more generally between 0.5 and 3% by weight. In one or more embodiments, the hydrocarbon feedstock contains metals. In one or more embodiments, the combined nickel and vanadium content of the hydrocarbon feedstock is less than 20 ppm by weight, preferably less than 10 ppm by weight, and even more preferably less than 5 ppm by weight.

[0153] According to one or more embodiments, the asphaltene content of the hydrocarbon feedstock is less than 4000 ppm by weight, preferably less than 1000 ppm by weight, even more preferably less than 300 ppm by weight.

[0154] According to one or more embodiments, the reaction effluent of the hydrotreating or hydroconversion reaction section Rl consists of a hydrocarbon cut, generally in mixed phase, comprising hydrogen, gases from cracking, and in particular HzS and NH3 from the reactions of said reaction section, in proportion to the sulfur and nitrogen content contained in the feed, possibly CO2 and other gases, light cuts such as LPG (or LPG for liquefied petroleum gas) from secondary reactions, and at least naphtha, and possibly the following hydrocarbon cuts: diesel, kerosene and / or unconverted residue, etc., depending on the nature of the feed and the type of reaction.

[0155] According to one or more embodiments, the first liquid effluent comprising at least one heavy fraction includes at least a portion of the heaviest fraction of the reaction section effluent, comprising naphtha, diesel, kerosene, and / or unconverted residue depending on the nature of the feedstock and the type of reaction. The first liquid effluent comprising at least one heavy fraction may also include an intermediate fraction of the reaction section effluent, possibly comprising diesel, kerosene, and / or naphtha depending on the nature of the feedstock and the type of reaction.

[0156] According to one or more embodiments, the first gaseous effluent comprising a light fraction includes at least a portion of the lightest fraction of the reaction effluent, comprising hydrogen, gases from cracking, and in particular H2S and NH3 from the reactions of the reaction section, in proportion to the sulfur and nitrogen content contained in the feed, possibly CO2 and other gases, light cuts such as LPG from secondary reactions, and at least naphtha.

[0157] According to one or more embodiments, the first liquid effluent comprising at least a light fraction includes a fraction of the reaction effluent comprising light cuts such as LPGs from secondary reactions, and at least naphtha.

[0158] According to one or more embodiments, the first gaseous effluent containing hydrogen comprises gases from cracking, and in particular H2S from the reactions in the reaction section, in proportion to the sulfur content in the feedstock, and possibly CO2. According to one or more embodiments, the second liquid effluent comprising at least one heavy fraction comprises the heaviest fraction of the effluent from the reaction section, including diesel, kerosene, and / or unconverted residue, depending on the nature of the feedstock and the type of reaction.

[0159] According to one or more embodiments, the second gaseous effluent comprising a light fraction includes a first intermediate fraction of the effluent from the reaction section, possibly including diesel, kerosene, and / or naphtha depending on the nature of the feedstock and the type of reaction.

[0160] According to one or more embodiments, the second liquid effluent comprising at least a light fraction includes the heaviest fraction of the first liquid effluent comprising at least a light fraction. The second liquid effluent comprising at least a light fraction may also include a second intermediate fraction of the reaction section effluent comprising diesel, kerosene, and / or naphtha, depending on the nature of the feedstock and the type of reaction.

[0161] According to one or more embodiments, the second gaseous effluent comprising hydrogen includes at least a portion of the lightest fraction of the reaction effluent, comprising hydrogen, gases from cracking, and in particular H2S from the reactions of the reaction section, in proportion to the sulfur content contained in the feed, possibly CO2 and other gases.

[0162] According to one or more embodiments, the head effluent comprises gases from cracking, and in particular H2S, possibly CO2 and other gases, LPGs, naphtha and possibly the stripping fluid.

[0163] According to one or more embodiments, the top gaseous fraction includes gases from cracking, and in particular H2S, possibly CO2 and other gases, LPGs.

[0164] According to one or more embodiments, the hydrocarbon liquid cut includes naphtha.

[0165] According to one or more embodiments, the bottom liquid comprises the heaviest fraction of the effluent from the reaction section, including diesel, kerosene and / or unconverted residue depending on the nature of the feed and the type of reaction.

[0166] In the installation described herein, the hydrotreating or hydroconversion reaction section Rl may comprise one or more reactors arranged in series or parallel, for example, two reactors arranged in series. Each reactor in the reaction section comprises at least one catalyst bed. The catalyst may be implemented as a fixed bed, an expanded bed, or a bubbling bed. In the case of a catalyst implemented as a fixed bed, it is possible to have several catalyst beds in at least one reactor. According to one or more embodiments, the hydrotreating or hydroconversion reaction section Rl is the reaction section of a hydrocracking plant.

[0167] According to one or more embodiments, the hydrotreating or hydroconversion reaction section Rl is the reaction section of a hydrodesulfurization plant for diesel or kerosene or vacuum distillate.

[0168] According to one or more embodiments, the hydrotreating or hydroconversion reaction section Rl is the reaction section of a naphtha hydrodesulfurization plant.

[0169] According to one or more embodiments, the hydrotreating or hydroconversion reaction section Rl is included in a boiling bed hydroconversion plant for residue or distillate or deasphalted oil.

[0170] The Cl separation column is designed to remove gases produced by cracking (generally called acid gases), and in particular the HzS produced by the reactions in the reaction section. This column is preferably stripped using a suitable stripping gas, such as a hydrogen-containing gas or steam. Steam is preferably used for this stripping.

[0171] According to the second aspect, the present description also relates to a method of implementing the installation according to the first aspect.

[0172] The method according to the invention, advantageously implementing the installation according to the invention, comprises the following steps:

[0173] - preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a charging furnace by means of at least one tubular feed-effluent heat exchanger E-2 comprising a plurality of tubes 10 through which a fluid flows and comprising an insert fixed to the upstream end of at least one of said tubes;

[0174] - heat and send the preheated hydrocarbon feed-hydrogen stream mixture to a hydrotreating or hydroconversion reaction section Rl using the feed furnace Fl;

[0175] - hydrotreating or hydroconverting the hydrocarbon feedstock in the hydrotreating or hydroconversion reaction section Rl comprising at least one reactor comprising at least one catalyst comprising at least one element selected from the elements of Group VIII of the periodic table

[0176] - to cool the reaction effluent from the hydrotreatment or hydroconversion reaction section Rl by means of said tubular charge-effluent heat exchanger E-2;

[0177] - lower the temperature of at least a portion of the reaction effluent from the tubular charge-effluent heat exchanger E-2 by means of a first air-cooled condenser A1 before it is sent to a high-pressure cold separator vessel B-2; - separate said at least a portion of the cooled reaction effluent in the high-pressure cold separator vessel B-2 to form a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen; and

[0178] - separate the first liquid effluent comprising at least a light fraction in a separation column Cl to form at least a bottom liquid and a top effluent.

[0179] According to one or more embodiments, the tubular feed-outlet heat exchanger E-2 is provided with a plurality of inserts fixed to the tubes of said tubular feed-outlet heat exchanger, and each insert comprising an element 100 having a rigid helical winding of a rod, preferably metallic, comprising several turns. Preferably, the element 100 is as described in relation to Figures 5 to 7 or 8, and comprises:

[0180] - a sequence of several successions of a first section SI of length L1 comprising a rigid helical winding of a rod, preferably metallic, comprising several turns and a second section S2 of length L2 comprising a straight rod, preferably metallic, and

[0181] - a first end connected to the fixing system 200 of the element 100 to an inlet of the tube 110.

[0182] Depending on one or more implementations, the process includes the following steps:

[0183] - pre-cool the entire reaction effluent from the hydrotreatment or hydroconversion reaction section Rl using a first heat exchanger El before sending it to the tubular charge-effluent heat exchanger E-2;

[0184] - lower the temperature of said cooled reaction effluent from the tubular charge-effluent heat exchanger E-2 by means of a first air cooler Al before sending it into said high-pressure cold separator vessel B-2;

[0185] - separate said first liquid effluent comprising at least a light fraction from the high-pressure cold separator flask B-2 into a medium-pressure cold separator flask B-4 to form a second liquid effluent (comprising at least a light fraction) sent to the separation column Cl and a second gaseous effluent comprising hydrogen;

[0186] - cool the bottom liquid from the separation column Cl and heat and send to said separation column Cl said second liquid effluent comprising at least a light fraction by means of a second heat exchanger E-4;

[0187] - heat said second liquid effluent comprising at least a light fraction from second heat exchanger E-4 before sending it to said separation column Cl by means of said first heat exchanger El.

[0188] Depending on one or more implementations, the operating conditions of the hydrotreating or hydroconversion reaction section Rl include at least one of the following characteristics:

[0189] - the temperature is between approximately 200 and approximately 550°C, preferably between approximately 200°C and 460°C; - the total pressure is between approximately 1 MPa and approximately 38 MPa, such as between 2 MPa and 20 MPa, preferably between 2.5 MPa and 18 MPa, and most preferably between 3 MPa and 18 MPa;

[0190] - The overall hourly spatial velocity of the liquid charge for each catalytic step is between approximately 0.05 h -1 and about 12 hours 1 , and preferably between approximately 0.1 h -1 and about 10 a.m. 1 ;

[0191] - the purity of the hydrogen used is between approximately 50 and 100% by volume relative to the volume of the hydrogen input (i.e., recycled hydrogen / make-up hydrogen mixture); and

[0192] - the quantity of hydrogen relative to the liquid hydrocarbon charge is between approximately 50 Nm 3 / m 3 and approximately 5000 Nm 3 / m 3 , preferably between approximately 50 Nm 3 / m 3 and approximately 2500 Nm 3 / m 3 .

[0193] Any catalyst known to a person skilled in the art may be used in the process according to this description, for example a catalyst comprising at least one element selected from the elements of Group VIII of the periodic table (groups 8, 9 and 10 of the new periodic table) and possibly at least one element selected from the elements of Group VIB of the periodic table (group 6 of the new periodic table).

[0194] For the implementation of the process according to the invention, a conventional hydroconversion catalyst can be used, comprising, on an amorphous support, at least one metal or metal compound having a hydro-dehydrogenating function. This catalyst can be a catalyst comprising metals from group VIII, for example nickel and / or cobalt, most often in combination with at least one metal from group VIB, for example molybdenum and / or tungsten. For example, a catalyst comprising 0.5 to 10% by weight of nickel (expressed as nickel oxide NiO) and 1 to 30% by weight of molybdenum, preferably 5 to 20% by weight of molybdenum (expressed as molybdenum oxide MoOa) relative to the total weight of the catalyst, can be used on an amorphous mineral support. The total content of metal oxides of groups VIB and VIII in the catalyst is generally between 5 and 40% by weight and preferably between 7 and 30% by weight relative to the total weight of the catalyst.The weight ratio (expressed on the basis of metal oxides) between metal(s) of group VIB and metal(s) of group VIII is generally from about 20 to about 1, and most often from about 10 to about 2. The support is, for example, chosen from the group formed by alumina, silica, silica-aluminas, magnesia, clays, and mixtures of at least two of these minerals. This support may also contain other compounds and, for example, oxides chosen from boron oxide, zirconia, titanium oxide, and phosphoric anhydride.

[0195] Another type of catalyst that can be used is one containing at least one matrix, at least one zeolite Y, and at least one hydro-dehydrogenating metal. The matrices, metals, and additional elements described previously can also be included in the composition of this catalyst. Advantageous zeolites Y are described in patent application WOOO / 71641, as well as patents EP0911077,

[0196] US4738940 and US4738941. According to one or more implementations, the high-pressure cold separator vessel B-2 is operated at a pressure lower than that of the hydrotreating or hydroconversion reaction section Rl or the high-pressure hot separator vessel Bl, for example a pressure 0.1 MPa to 1.0 MPa lower than that of the hydrotreating or hydroconversion reaction section Rl or the high-pressure hot separator vessel Bl.

[0197] The temperature of the high-pressure cold separator vessel B-2 is generally kept as low as possible given the available cooling resources. This is to maximize the purity of the recycled hydrogen. The temperature of the high-pressure cold separator vessel B-2 is typically between 20°C and 100°C, preferably between 35°C and 70°C. The first liquid effluent, containing at least a light fraction, from the high-pressure cold separator vessel B-2 is sent to the separation column Cl, preferably a stripper column, ideally equipped with the reflux vessel B-6.

[0198] Depending on one or more implementations, the cooled reaction effluent is sent to the optional high-pressure hot separator vessel Bl, which is operated at a lower pressure, for example, 0.1 MPa to 1.0 MPa lower than that of the hydrotreating or hydroconversion reaction section Rl. The temperature of the high-pressure hot separator vessel Bl is generally between 200°C and 450°C, preferably between 250°C and 380°C, and most preferably between 260°C and 360°C.

[0199] According to one or more implementations, the first liquid effluent including at least a heavy fraction from the high-pressure hot separator tank Bl is sent into a first valve Vl or an optional turbine and directed to the optional medium-pressure hot separator tank B-3 whose pressure is chosen so as to be able to supply the optional medium-pressure cold separator tank B-4 with the second liquid effluent including at least a heavy fraction from the medium-pressure hot separator tank B-3.

[0200] Depending on one or more implementations, the B-3 medium-pressure hot separator tank is operated at a pressure between 1.0 and 5.0 MPa, preferably between 1.5 and 3.5 MPa. The temperature of the B-3 medium-pressure hot separator tank is generally between 150°C and 380°C, preferably between 200°C and 360°C.

[0201] In one or more implementations, the first liquid effluent, including at least a light fraction, from the high-pressure cold separator vessel B-2 is expanded through a second valve V-2 or an optional turbine and directed to the optional medium-pressure cold separator vessel B-4. The total pressure of the medium-pressure cold separator vessel B-4 is preferably that required to efficiently recover the hydrogen contained in the second gaseous effluent containing hydrogen separated in said vessel B-4. This hydrogen recovery is preferably carried out in a pressure-reversing adsorption unit. The total pressure of the medium-pressure cold separator vessel B-4 is generally between 1.0 MPa and 5.0 MPa, preferably between 1.5 MPa and 3.5 MPa. The temperature of the medium-pressure cold separator vessel B-4 is generally between 20°C and 100°C, preferably between 25°C and 70°C.

[0202] The bottom liquid (line 26) of the Cl separation column can be heated via the fourth heat exchanger E-4 before being sent via line 27 to a fractionation section (not shown) which allows the separation of naphtha, kerosene, diesel and residue cuts.

[0203] The inventors have demonstrated that it is possible to implement inserts adapted to tubular feed-effluent type heat exchangers of a hydrotreatment or hydroconversion installation of a hydrocarbon feed, capable of meeting significant pressure drop constraints, and in particular of operating with a minimum variation in pressure drop, and thus conferring the following advantages to the installation and the process according to the invention:

[0204] - increase the processing capacity of the installation / process, and / or

[0205] - lower capital expenditure (CAPEX) on heat exchangers by allowing the use of smaller heat exchangers for a given plant / process capacity, and / or

[0206] - to provide operational flexibility of the installation and the process in case of variation of the load treated, particularly in terms of fouling power.

[0207] In some cases such as that of a detailed cold scheme below in relation to figure 2, it is also very advantageously possible to preheat the hydrocarbon feed-hydrogen flow mixture more efficiently so that the required consumption of the Fl feed furnace is lower, limiting the consumption of CO2.

[0208] Figures 1, 2 and 3 show the same numbering for the same equipment in the hydrotreatment or hydroconversion plant.

[0209] Figure 2 illustrates an example of a first embodiment of the invention.

[0210] According to this first embodiment of the invention, the hydrotreating or hydroconversion installation and process follow a so-called "cold" scheme, which is a classic hydrotreating scheme for middle distillates, in which the separation section, comprising at least one separation vessel, is operated at a low temperature. This type of scheme limits hydrogen losses, particularly because the transfer of hydrogen into the liquid phase is thermally limited, compared to a so-called "hot" scheme. However, this type of cold scheme generally requires a larger heat exchange surface area and implies higher furnace power consumption and a larger separation section.

[0211] The hydrotreatment or hydroconversion installation according to this first embodiment of the invention includes all the elements of the installation described in relation to Figure 1, which are not repeated here, and further includes the following element which is no longer optional: - the medium-pressure cold separator tank B-4.

[0212] Preferably, and as illustrated in Figure 2, the following devices are also no longer optional:

[0213] - the first El heat exchanger, and

[0214] - the second heat exchanger E-4.

[0215] The integration of inserts in the tubular charge-effluent heat exchanger E-2 is particularly advantageous in the context of a cold scheme such as that applied by the installation / process according to this first embodiment of the invention.

[0216] While this first embodiment allows for increased processing capacity, reduced capital expenditures (CAPEX) – notably through the use of smaller heat exchangers for a given processing capacity – and greater operational flexibility for handling variable loads that can lead to varying degrees of fouling, a major advantage of this first embodiment lies in the reduction of CO2 emissions. Indeed, the gains in fuel consumption for the charge furnace Fl, and potentially for the air-cooled condenser Al, due to improved heat exchange and reduced fouling, are significant and allow for limiting CO2 emissions and thus the environmental impact of the process.

[0217] Figure 3 illustrates an example of a second embodiment of the invention.

[0218] According to this second embodiment of the invention, the hydrotreating or hydroconversion installation and process follow a so-called "hot" scheme, which is also a classic hydrotreating scheme for heavier feedstocks such as middle distillates, in which the separation section includes at least one separation vessel operated at high temperature. This type of scheme, compared to the cold scheme, reduces the heat exchange surface area, decreases the consumption of the feed furnace, and allows for the processing of heavier feedstocks. However, hydrogen losses due to dissolution, and consequently the hydrogen replenishment, are greater. The cost of hydrogen can make this type of process economically unviable. Generally, in a hot scheme, the hot separation vessel(s) operate at the outlet temperature of the reactor in the hydrotreating or hydroconversion reaction section (Rl) and at the reactor pressure.

[0219] In this type of hot process, the overall thermal performance of the feed / effluent heat exchangers is generally limited by the specifications imposed on the inlet and outlet. Therefore, improving the heat transfer of the tubular feed-effluent heat exchanger(s) incorporating inserts according to the invention has little overall impact on the energy consumption of the feed furnace Fl, but allows for increased processing capacity and / or reduced capital expenditures, particularly by enabling the use of smaller heat exchangers for a given processing capacity, and / or providing operational flexibility to handle loads with varying fouling potential.

[0220] The hydrotreatment or hydroconversion installation according to this second embodiment of the invention comprises all the elements of the installation described in relation to Figure 1, which are not repeated here, the following elements no longer being optional:

[0221] - the B-4 medium-pressure cold separator tank,

[0222] - the high-pressure hot separator vessel Bl, and

[0223] - the medium-pressure hot separator tank B-3.

[0224] Preferably, and as illustrated in Figure 3, the following devices are also no longer optional:

[0225] - the first El heat exchanger,

[0226] - the second heat exchanger E-4,

[0227] - the second air-cooled condenser A-2, and

[0228] - the E-3 external flow heat exchanger.

[0229] Inserts

[0230] Advantageously, the E-2 tubular charge-effluent heat exchanger is equipped with a plurality of inserts fixed to the tubes of said charge-effluent heat exchanger.

[0231] Figures 5 to 8 illustrate examples of inserts that can be integrated into the tubes of the E-2 tubular charge-effluent heat exchanger(s).

[0232] Preferably, each insert comprises an element 100 having a rigid helical winding of a rod, preferably metallic, comprising several turns.

[0233] According to one or more embodiments, represented in figures 5 to 7, the insert comprises an element 100 comprising a sequence of several successions of a first section SI of length L1 comprising a rigid helical winding of a rod, preferably metallic, comprising several turns and of a second section S2 of length L2 comprising a straight rod, preferably metallic.

[0234] Element 100 includes a first end, advantageously connected to a fixing system 200 of said element 100 to an inlet of said tube 110, visible in figure 6.

[0235] The sequence consisting of a first section SI comprising a rigid helical winding of a rod with several turns and a second section S2 comprising a straight rod is repeated n times in the sequence.

[0236] The sequences are preferably identical to each other, i.e., have the same geometric characteristics (e.g., same lengths L1 and L2, same pitch of the first section, same rod thickness, etc.). However, a sequence of different sequences does not fall outside the scope of the present invention. For example, the length L1 and / or L2 may be the same from one sequence to the next or may be different. For example, the length L1 of the first section SI of the first sequence in the sequence may be different from the length L1 of the section SI of the subsequent sequences, because it is the first section SI of the first sequence that primarily rotates the rest of the insert.

[0237] The total length of the insert L| is essentially equal to the sum of the lengths L1 and L2 of all the sequences S1 / S2. The length Li can be equal to n times the sum of the lengths L1 and L2 if the lengths L1 and L2 are identical from one sequence to the next.

[0238] Permanent joining means can connect the first section SI and the second section S2, as well as the sequences between them, to form an element 100 in the form of a single part. Such permanent joining means are, for example, welds or any other suitable permanent joining means for said parts. Alternatively, the first section SI and the second section S2, as well as the sequences between them, form an element 100 in the form of a single part without joining means, the different parts being manufactured directly as a single piece.Alternatively (not shown), non-permanent, preferably detachable, means of assembly, such as a hook-washer assembly or any other suitable means of assembly, are used to connect the first section SI and the second section S2, as well as the successions between them to form an element 100 in the form of separate parts connected in such a way as to be mechanically joined.

[0239] The first SI section of the sequence positioned first in the chain from the entrance of tube 110 originates at the first end of element 100.

[0240] Element 100 can be static, but is preferably rotationally mobile during its operation within the heat exchanger tube 110. When element 100 is rotationally mobile, the insert also scrapes the tube walls, further reducing pressure drop compared to a static insert, as explained in detail below.

[0241] In the case of a static element 100, the first end of the element 100 may be attached to a mechanical link of the fastening system 200, which allows the element 100 to be positioned axially and securely within the tube 110 through which a fluid flows. The fastening of the static element 100 within the tube may be reinforced by additional fastening means to the tube, which may be located at a second end opposite the first end and / or along the element 100. The static element 100 may also be secured without dedicated fastening means.

[0242] Preferably, the element 100 is rotationally mobile, and the first end of the element 100 is then fixed to a mechanical link 220 of the fixing system 200 which allows the free rotation of said element 100 on itself around the axis Z of the tube 110 under the action of a fluid passing through said tube 110, as shown in figure 6, and said rotationally mobile element 100 having a second free end opposite said first end.

[0243] Advantageously, during its operation in the heat exchanger tube, the presence of element 100 increases the turbulence of the circulating fluid, improves heat exchange, and homogenizes the temperature of the circulating fluid throughout the tube's cross-section. This prevents the formation of hot spots on the tube wall and consequently significantly reduces the risk of solid deposit formation, improving heat transfer, which is typically hampered by this type of deposit. The insert, when rotated, also scrapes away any deposits that may have formed on the wall, thus reducing fouling. In addition to reducing deposits, heat transfer is improved due to the increased turbulence of the circulating fluid caused by the presence of the insert, which enhances convective heat transfer.Indeed, the mere presence of the insert, and even more so its rotation when element 100 is rotating, creates turbulence that leads to increased heat transfer by reducing the thickness of the heat transfer boundary layer and thus the transfer resistance near the wall. The heat transfer performance of tubular heat exchangers incorporating such inserts is therefore improved, as is the lifespan of the heat exchangers.

[0244] In the case of a rotating element 100, the threshold (threshold speed) for initiating rotation of an insert corresponds to the minimum surface velocity of the circulating fluid that allows the insert's moving element to rotate. The moving element, rotating in the opposite direction to the helical winding of the spring, with a speed that depends on its weight, geometric characteristics, flow rate, viscosity, and density of the circulating fluid, therefore has its own specific threshold for initiating rotation.

[0245] The presence of an insert in the heat exchanger tube induces a pressure drop.

[0246] Within the framework of the present invention, the inserts of the tubes of the E-2 tubular feed-effluent heat exchanger have the capacity to limit the pressure drop associated with the operation of the insert, and are thus particularly well-suited for use in two-phase tubular heat exchangers that may have more demanding operating conditions with respect to pressure drop, i.e., have a low acceptable pressure drop threshold, as is the case in the field according to the invention. The insert can, in particular, be sized to meet the pressure drop requirements of an existing hydrotreatment or hydroconversion plant.The insert comprising a series of several successions of a first section SI comprising a rigid helical winding of a rod comprising several turns followed by a second section S2 comprising a straight rod, in particular according to the specificities described below, surprisingly improves heat exchange, and possibly reduces fouling, while limiting the pressure loss induced by the insert.

[0247] The pressure drop is further reduced if element 100 of the insert is rotatable. The number of S1 / S2 cycles, denoted n, is determined to achieve optimal heat transfer.

[0248] Preferably, n, which is a positive integer, is between 2 and 15, preferably between 2 and 10, more preferably between 4 and 8.

[0249] Preferably, the pitch pl of the first SI section is between 10 mm and 50 mm, preferably is between 20 mm and 40 mm.

[0250] The pitch can be defined in general terms as a function of the angle of inclination of the turns and the diameter of the turns of the rigid helical winding D, according to the following relationship: pitch = (KD) / tana.

[0251] The turn inclination angle α is defined with respect to the winding axis coinciding with the Z-axis of the heat exchanger tube in which the insert is mounted. The angle αi refers to the turn inclination angle of the first SI section.

[0252] From one S1 / S2 sequence to another in the chain, the length of a given section (S1, S2) is preferably identical. In this case, the lengths L1 and L2 can be estimated using the equations

[0253] (1) and (2) below:

[0254] (1) L1 ~ (Li / n). (APs / (APi -APv))

[0255] (2) in which:

[0256] (3) Li: the total length of the sequence of S1 / S2 (i.e. approximately the length of the insert according to the first embodiment),

[0257] (4) n: the number of successions S1 / S2 of the insert,

[0258] (5) APs: the maximum additional pressure drop specified for one meter of heat exchanger tube,

[0259] (6) APi: the pressure drop generated for one meter of heat exchanger tube equipped with an insert.

[0260] (7) APi can be calculated or measured, and the insert used is a classical rigid helical winding of given geometric parameters.

[0261] (8) APv: the pressure drop generated by one meter of exchanger tube without insert.

[0262] Advantageously, the length L2 of the second section can be expressed as follows: (2) L2 = (Li / n) - Ll

[0263] Preferably, the length L1 of the first SI section is between 50 mm and 12000 mm, preferably between 500 mm and 5000 mm.

[0264] Preferably, the length L2 is between 500 mm and 12000 mm, preferably between 500 mm and 5000 mm.

[0265] The first section SI and the second section S2 are joined together, as are the successions between them, and can form an element 100 in the form of a single piece (a final single piece), typically when permanent joining means such as welds connect the first section SI and the second section S2 on the one hand, and the successions between them on the other hand.

[0266] The total length of the insert is less than or equal to the total length of tube 110 of the heat exchanger, and preferably between 50% and 100% of the total length of tube 110 of the heat exchanger: the total length of the insert is preferably between Lt / 2 and Lt , with L t the length of the 110 tube of the exchanger.

[0267] The total length of the insert may be slightly less than the tube length to take into account possible elongation due to mechanical stress applied by the fluid and / or thermal expansion.

[0268] The E-2 heat exchanger tube 110 can have a total length between 500 mm and 6000 mm, preferably between 1000 mm and 6000 mm.

[0269] The rigid helical winding of the first section SI has a diameter D, which corresponds to the diameter of the turns of the winding.

[0270] Advantageously, the diameter D of the turns of the rigid helical winding of the first section SI is greater than or equal to 80% of the diameter Dt of the tube 110 of the heat exchanger, preferably greater than or equal to 90% of the diameter Dt, in order to generate optimal turbulence of the circulating fluid and possibly to scrape deposits on the tube wall efficiently. Preferably, the diameter D of the turns of the rigid helical winding of the first section SI is between 80% and 100% of the diameter Dt of the heat exchanger tube 110, more preferably between 85% and 100% of the diameter Dt. In the case of a rotating element 100, the diameter D of the turns of the rigid helical winding of the first section SI is preferably between 80% and 99% of the diameter Dt of the heat exchanger tube 110, more preferably between 85% and 95% of the diameter Dt.

[0271] The diameter of the tubes (internal diameter Dt) can be between 10 mm and 100 mm, preferably between 10 mm and 50 mm.

[0272] Advantageously, a space "c" exists between the rigid helical winding of section SI and the inner wall of tube 110 such that said rigid helical winding of the element does not touch the tube wall, in the case of the rotating insert, as referenced in Figure 7, which shows a rear view of a portion (part of the first section SI) of the insert and the heat exchanger tube E-2, in order to avoid damaging the tube wall, for example, creating scratches that could form surface irregularities that could promote corrosion. This space "c" is preferably between 1 mm and 3 mm.

[0273] The rigid helical winding of the SI section can have a cross-section of various shapes, and preferably a circular or square cross-section, and more preferably a circular cross-section. In the case of a square cross-section or another shape, the diameter of the cross-section is understood to be an equivalent diameter D_eq, defined as follows: D_eq = 4 * Cross-sectional area / perimeter of the cross-section.

[0274] The rod, preferably metallic, forming the rigid helical winding of section SI has a diameter el, and the straight rod, preferably metallic, of the second section S2 has a diameter e2. The diameters el and e2 are preferably between 0.5 mm and 5 mm, more preferably between 1 mm and 3 mm.

[0275] The diameters el and e2 can be identical or different. Having identical diameters el and e2 has the advantage of simplifying the manufacture of the insert.

[0276] The direction of the rigid helical winding of the SI section, which can also be defined as the direction of the pitch of the turns, can be clockwise, or counterclockwise (relative to the direction of fluid flow in the tube, represented by an arrow along the Z axis in the figures).

[0277] The first end of the element 100, preferably attached to the mechanical link 220, may include a ring la or any other means of attachment to the mechanical link 220.

[0278] The insert material can be carbon steel, stainless steel, or any other metal or metal alloy such as Inconel®, providing the required rigidity and preferably resistance to high temperatures and corrosion. The insert material is preferably less hard than the heat exchanger tube material to prevent tube degradation.

[0279] For highly corrosive fluids, the material forming the insert can be coated with a layer of protective material, typically a polymer layer.

[0280] The material forming the insert can alternatively be a polymer or composite material (metal or metal alloy with a polymer material, or different types of polymers, or a composite material combining different types of reinforcements, such as fibers, particles, etc., with different matrices, such as a polymer, metallic or ceramic matrix).

[0281] The rigid helical winding of the first section SI and the straight stem of the second section S2 of the element are robust elements, i.e., with a low risk of breakage.

[0282] The system for attaching the insert to the tube can be a traditional attachment system, for example, as described in patents FR2612267 and FR2639425 for an insert with a rotating movable element 100. In this case, the attachment system is advantageously arranged along the Z-axis of the heat exchanger tube so that the movable element of the insert can rotate about said axis. The attachment system is typically positioned at the tube inlet, and the rotating movable element of the insert is connected to the attachment system and positioned downstream in the tube. An example of a traditional attachment system 200 is shown in Figure 6 and includes a bearing 230 and the mechanical linkage 220, typically formed by a rotating trunnion. This trunnion 220 is fixed to the movable element 1 of the insert so that the insert is free to rotate about the Z-axis of the tube 110.The bearing 230 comprises a stirrup-shaped portion 230a, typically a single-piece component made of a rigid material capable of elastic deformation, the end of which has two arms for attachment to the tube 110, and a central portion 230b comprising an opening for retaining the trunnion 220. The two arms of the stirrup-shaped portion 230a are separated by a distance such that the arms can be forcibly engaged in an open end of the tube 110 to bear elastically against the inner wall of the tube, thus making said portion 230a of the bearing 230 rigidly fixed to the tube 110. The trunnion 220 comprises a straight cylindrical rod engaged in the opening of the central portion 230b of the bearing 230 and a hook-shaped end 210 that can be hooked onto the ring or any other fastening means included in the first end of element 100 is mobile and rotating.The other end of the trunnion 220 has a head in the form of a washer suitable for holding it captive in the bearing 230. An anti-wear washer can also be interposed between the bearing and the head of the trunnion.

[0283] The system for attaching the insert to the tube can also be configured so that the insert element 100 is fixed, i.e., static, within the insert (no rotation of the insert). Such a fastening system may include various means of attaching the element 100 to the tube, at the inlet and / or inside the tube, and possibly at the tube outlet, for example, but not limited to:

[0284] - a transverse rod respectively at the inlet and outlet of the tube and to which element 100 is connected;

[0285] - a traditional fastening system similar to that shown in Figure 6 and described above, but without a bearing and without rotation of the trunnion,

[0286] - at least one ring outside the tube and larger than the diameter of the tube, connected to element 100.

[0287] The insert can also be fixed in the tube without a dedicated fixing system, for example in the case where the diameter of the rigid helical winding is equal to the diameter of the tube, due to the stiffness of the helical winding which is in contact with the wall of the tube and fixes the insert in the tube.

[0288] Each insert advantageously includes its own tube fixing system, although a common fixing system shared between the inserts of the other E-2 heat exchanger tubes can be used.

[0289] According to one or more embodiments, as illustrated in Figure 8, the rotating element 100 of the insert further comprises a rotating drive piece 300 positioned upstream and connected to the first section SI of the sequence positioned first in the assembly. The rotating drive piece 300 is thus positioned between the fastening system 200 and the first section SI of the first sequence in the assembly of the insert element 100. The rotating drive piece comprises a shaft 3a coaxial with the helical winding of the first section SI, said shaft being provided with at least two blades 300b integral with the shaft 3a.

[0290] The rotating drive part 300 has Nb blades, Nb being an integer between 2 and 6, preferably between 3 and 5.

[0291] This type of insert has a lower rotation threshold compared to existing rigid helical-wound rotary inserts. The reduced rotation threshold speed ensures a mechanical effect even at low fluid flow rates in the feed-effluent heat exchanger tube, thus improving the versatility of this insert.

[0292] The rotating drive part 300 has a length La, which corresponds substantially to the length of the shaft 3a, and which is preferably between 10 mm and 500 mm, preferably between 20 mm and 200 mm.

[0293] The total length of such an insert is essentially made up of the sum of the length La of the rotating drive part 300 and the length U of the sequence of successions S1 / S2, the length Li being able to be equal to n times the sum of the lengths L1 and L2 if the lengths L1 and L2 are identical from one succession to the other.

[0294] The length L3 of a blade is the distance, along the Z-axis, between the leading edge of the blade and its trailing edge. The leading and trailing edges follow each other in the direction of fluid flow, with the leading edge initially facing the fluid.

[0295] Each blade has a pitch angle P3, which can be defined between the Z-axis and the tangent to the mean camber line of the blade at a given point on the blade. This pitch angle can be variable or fixed along Z and / or r in a cylindrical coordinate system.

[0296] Preferably, all the blades are identical, that is to say, they have the same geometric characteristics (length, diameter, thickness, etc.).

[0297] The 300 rotating drive part of the insert is a robust element, i.e., one with a low risk of breakage.

[0298] The material forming the rotating drive part 300 of the rotating mobile element 100 of the insert can be one of those already listed above for the insert, and can be identical or different from the material used for the linking of sections S1 / S2.

[0299] The insert example shown in Figure 8 has a rotating screw-shaped drive 300, with blades forming spirals, and the pitch of each blade p3 (pitch of revolution) is between 10 mm and 50 mm, more preferably between 15 mm and 20 mm. The pitch of revolution of the blades is advantageously adjusted to generate the torque necessary to rotate the insert while respecting the pressure loss constraint.

[0300] Advantageously, the screw-shaped rotating drive piece 300 has four identical blades 300b. The blades wind around the shaft 3a along the entire length of the piece, giving it its screw shape. The length L3 of the rotating drive piece 300 is also the length of one blade.

[0301] The number of turns (also called revolution) for the screw-shaped drive part 300 is greater than 1, for example equal to 5 as illustrated in Figure 8.

[0302] The shaft 3a of the rotating drive component 300 has a diameter da3, preferably between 1 mm and approximately 50% of the tube's internal diameter, typically between 1 mm and 50 mm, but more preferably between 2 mm and 10 mm. The diameter of shaft 3a influences the fluid passage area, and large values ​​of da3 increase the fluid's surface velocity. The diameter da3 of shaft 3a can be constant along the Z-axis, as shown in Figure 8. Alternatively, it can be variable along the Z-axis.

[0303] The blades of the rotating drive component 300 have a diameter dr3, preferably greater than or equal to 80% of the diameter Dt of the heat exchanger tube 110, and more preferably greater than or equal to 90% of the diameter Dt. Preferably, the diameter dr3 of the blades is between 80% and 99% of the diameter Dt of the heat exchanger tube 110, and more preferably between 85% and 95% of the diameter Dt. Advantageously, there is a gap between the tips of the blades of said component 300 and the inner wall of the tube 110, so that the blades do not touch the tube wall, thus preventing damage to the tube wall. This gap is preferably between 1 mm and 3 mm. This gap is preferably constant along the axis of the shaft. However, it can vary along said axis, for example decrease, preferably continuously, from the inlet to the outlet of the tube (in the direction of fluid flow in an operating situation of the insert).

[0304] Preferably, the diameter dr3 of the blades is between 8 mm and 99 mm, preferably between 8.5 mm and 95 mm, more preferably between 8.5 mm and 50 mm, and even more preferably between 10 mm and 25 mm. The diameter of a blade is constant, as shown in Figure 8, or may vary in the direction of the shaft axis.

[0305] The blades have a thickness e3, preferably between 0.3 mm and 3 mm. The blade thickness must be minimal while still meeting mechanical constraints, to reduce size and thus pressure loss.

[0306] The blade surface is the surface formed by the junction between two propeller curves with two diameters of revolution: da3 and dr3. The angle of inclination P3 of the blades of the drive part shown in figure 6 is constant along Z, and varies with the radius r according to the equation: P3=arctan((2ît * r) / p3), the pitch p3 being constant.

[0307] The shaft 3a and the blades can be a single unit (i.e. manufactured in one piece), or alternatively be separate units fixed to each other for example by welding or any other rigid fastening means allowing the whole to be joined together.

[0308] The rotating drive piece 300 can be connected to the rigid helical winding of the first section SI of the sequence positioned first in the assembly (starting from the inlet of the tube 110) by any means of connection allowing the joint rotation of said rigid helical winding with the drive piece 300, and thus ultimately of the moving element 100, about itself around the Z-axis under the action of a fluid flowing through the tube 110. For example, the rotating drive piece 300 has an end 3d, opposite end 3c, which has a hook connected to a ring la carried by the end of the rigid helical winding of the first section SI of the sequence positioned first. The second end of the element 100, at the end of the sequence of the first and second sections SI and S2, is free.Any suitable means of fastening other than a hook-washer assembly can be used to fasten the rotating drive part 300 and the succession of sections S1 / S2.

[0309] Any other drive part configuration suitable for reducing the insert's rotation threshold while limiting pressure loss can be associated with the sequence of element 100 of the insert integrated with the tubular charge-effluent heat exchanger E-2.

[0310] According to one or more embodiments, the installation further comprises at least one additional heat exchanger, different from the tubular charge-effluent heat exchanger E-2, and which may be single-phase or two-phase, comprising a plurality of tubes 110 through which a fluid flows and which are fitted with an insert.

[0311] The insert can be a known prior art insert as illustrated in Figure 4, or an insert similar to those used in the tubular charge-effluent heat exchanger E-2 as described above, particularly with reference to Figures 5-8.

[0312] Figure 4 illustrates a rotating insert comprising a rigid helical metal winding with a plurality of turns of length L, diameter D, pitch p, and angle of inclination α(a) defined with respect to the central axis of the winding, which coincides with the Z-axis of the heat exchanger tube in which the insert is mounted. The metal rod forming the winding has a thickness e. The metal winding has a free end and an end fitted with a ring for attachment to a tube mounting system as described in relation to Figures 5-7. Examples

[0313] The examples below are intended to show some of the advantages of the installation and process according to the invention comprising tubular charge-effluent type heat exchangers incorporating inserts.

[0314] The hydrocarbon feedstock is a cut with boiling points between 140°C and 375°C and the following characteristics:

[0315] - Density: 0.855

[0316] - Sulfur content (% by weight): 1.2

[0317] - Nitrogen content (ppm by weight): 309.

[0318] The installation comprises two trains of 5 E-2 tubular heat exchangers. The tubes are fitted with inserts.

[0319] The installation follows the cold chain scheme as shown in Figure 2, detailed below: The hydrocarbon feedstock 1 is mixed with a hydrogen stream 4, and the mixture is then partially heated by the reaction effluent 8 from the hydrotreating reactor Rl in the tubular feedstock-effluent heat exchanger trains E-2. The remaining heating is provided by the feed furnace Fl, which also serves to start the unit. Once heated, the hydrocarbon feedstock-hydrogen stream mixture is sent to the hydrotreating reactor Rl. The effluent 8 exiting the hydrotreating reactor is partially cooled in the first heat exchanger El, which also heats the feedstock 24 in the separation column Cl, then is cooled in the tubular feedstock-effluent heat exchanger trains E-2, and finally cooled via the air-cooled condenser Al.A first separation is carried out in the high-pressure cold separator vessel B-2 to recover the gas fraction containing hydrogen 15, which is purified in the amine scrubbing unit C-2, compressed by the compressor Kl, and then recycled to the hydrotreating reactor Rl (flow 4) with a supply of fresh compressed hydrogen (flow 3) by the compressor K-2. The liquid fraction 20 from vessel B-2 is sent to a medium-pressure cold separator vessel (lower than that of B-2) B-4 to recover the liquid fraction sent to the separation column Cl and to fractionate the products of interest (27, 30).

[0320] Based on the material and energy balances at the end of the cycle (case “End of Run” in English), part of the process (exchanger E-2, furnace Fl, air condenser Al, hydrogen compressor of recycled and fresh Kl and K-2) is simulated using the Grayson Streed thermodynamic model, in the Aspen simulation software and the Aspen Exchanger Design & Rating (EDR)™ module.

[0321] Three simulation examples are presented below, differing primarily in the gain on the heat transfer coefficient and the thermal resistance coefficient due to fouling on the tube side that are taken into account. The results of these three examples are compared to those of the same process in which the tubular heat exchangers do not include inserts (REF case).

[0322] Example 1 (according to the invention):

[0323] In example 1, we consider a gain in the heat transfer coefficient on the tube side of 30%, i.e., a value of 1690 W / m 2 .K versus 1300 W / m 2 .K for the REF case (bare tubes without inserts).

[0324] In example 1, no effect on fouling is taken into account: the thermal resistance coefficients due to fouling considered in the calculations are 0.0003 m 2 .K / W tube side and 0.0007 m 2 .K / W grille side.

[0325] Example 2 (according to the invention):

[0326] In example 2, we consider both a gain on the heat transfer coefficient and a reduction in fouling related to the presence of inserts in the tubes.

[0327] The gain in the heat transfer coefficient on the tube side taken into account is 30%, i.e., a value of 1690 W / m 2 .K, as in example 1.

[0328] The thermal resistance coefficient due to fouling taken into account is 0.0001 m 2 .K / W on the tube side, and it is 0.0007 m 2 .K / W grille side as in example 1.

[0329] Example 3 (according to the invention):

[0330] In example 3, we consider both a gain on the heat transfer coefficient and a reduction in fouling related to the presence of inserts in the tubes.

[0331] The gain in the heat transfer coefficient on the tube side taken into account is 50%, i.e., a value of 1950 W / m 2 .K.

[0332] The thermal resistance coefficient due to fouling taken into account is 0 m 2 .K / W on the tube side, and it is 0.0007 m 2 .K / W grille side as in example 1.

[0333] The results of examples 1 to 3 and the reference case with bare tubes (REF case) are presented in Table 1 below. Table 1

[0334] The examples show significant gains in energy consumption and limitation of CO2 emissions generated at the charging furnace and air condenser level.

[0335] According to example 1, it is possible to limit fuel consumption at furnace Fl by approximately 535 tonnes of oil equivalent (toe) per year, which is equivalent to approximately 1605 tonnes of CO2 avoided per year (-1% compared to the REF case of E-2 heat exchangers without inserts). A CO2 saving of 34.7 L is also achieved because the effluent 10 exits at a lower temperature and requires less electricity consumption at the air-cooled condenser Al.

[0336] According to example 2, both improved heat transfer and reduced fouling are considered. When the fouling resistance coefficient is reduced by 66%, in addition to a 30% reduction in the heat transfer coefficient on the tube side, fuel consumption in furnace Fl is reduced by approximately 1094 tonnes of oil equivalent per year, which is equivalent to approximately 3283 tonnes of CO2 avoided (-2% compared to the REF case). 71 tonnes of CO2 per year are also avoided at the air-cooled condenser Al.

[0337] According to example 3, when the introduction of inserts completely eliminates fouling on the tube side and the improvement in the tube-side heat transfer coefficient is 50%, fuel consumption in furnace Fl is reduced by approximately 1376 tonnes of oil equivalent per year, equivalent to approximately 4129 tonnes of CO2 avoided (-2.5% compared to the REF case). 89 tonnes of CO2 per year are also avoided at the air-cooled condenser Al.

[0338] Adding inserts to the E-2 tubular feed-effluent heat exchangers results in a pressure drop (pressure loss "Delta P") of approximately 8 mbar / m. Table 2 below shows the pressure drop in the E-2 tubular feed-effluent heat exchangers and the increase in compressor power Kl required to compensate for this pressure drop.

[0339] Table 2

[0340] The installation of inserts in the E-2 tubular charge-effluent heat exchangers results in an additional pressure drop, requiring a 2.3% increase in compressor power (Kl), which corresponds to an increase in CO2 emissions of approximately 0.121 t / year. Compared to the savings from reduced fuel consumption in the Fl charge furnace, these emissions are negligible.

[0341] Example 4 (according to the invention):

[0342] Example 4 below is based on calculations, and aims to show the effects in terms of heat transfer gain and pressure drop minimization of an example of a tubular charge-effluent heat exchanger insert of an installation and process according to the invention.

[0343] In this example, we compare a reference case of a tube without an insert with a case of a tube containing an insert as illustrated in Figure 5, in which element 100 is fixed (static) and comprises a sequence of 6 times (n) the succession of a first section SI of length L1 = 0.56 m and a second section S2 of length L2 = 0.44 m. The total length of element 100 (and therefore of the insert) is 6 m and corresponds to the length of the tube.

[0344] The insert's metal rods (helical winding and straight rod) are made of carbon steel and have a circular cross-section. The helical winding is clockwise relative to the insert's position at the tube inlet.

[0345] The main geometric parameters of the insert are summarized in Table 3 below, which also gives the results of pressure loss induced by the presence of the insert in the tube.

[0346] The flow conditions for the examples are as follows:

[0347] - liquid velocity = 0.25 m / s;

[0348] - gas velocity = 2.82 m / s. The calculations of pressure loss and heat transfer efficiency on the tube side are carried out for the fixed (static) insert.

[0349] Table 3

[0350] In Table 3:

[0351] - D and L are respectively the diameter and total length of the insert;

[0352] - L1 and L2 are respectively the lengths of section SI (rigid helical metal winding) and section S2 (straight metal rod) of element 100 of the exemplified insert. The succession of sections S1 / S2 is repeated n=6 times, the total length of the insert thus being 6 m;

[0353] - pl is the pitch of the first SI section (rigid helical metal winding) of the exemplified insert;

[0354] - el and e2 are respectively the thicknesses of sections SI and S2 of the exemplified insert.

[0355] To evaluate the performance of the exemplified insert, we compare the heat transfer obtained with the reference case of the tube without the insert, and the pressure loss induced by the presence of the insert.

[0356] The results obtained indicate a gain in heat transfer on the tube side of 111% in the case of the tube with the exemplified insert compared to the reference case of the tube without insert, which makes it possible to significantly improve the heat transfer performance of the tubular charge-effluent heat exchanger integrating the insert.

[0357] The results also show that the exemplified insert generates a pressure drop of 13 mbar / m, i.e. an additional permissible pressure drop of 8 mbar / m compared to the reference case of the tube without insert which has a pressure drop of 5 mbar / m, which is well suited to the operation of tubular feed-effluent heat exchangers for installation and hydrotreatment or hydroconversion processes of a hydrocarbon feed according to the invention.

Claims

1. Claims 1. Hydrotreatment or hydroconversion plant for a hydrocarbon feedstock, comprising: - at least one tubular feed-effluent heat exchanger (E-2) configured to: preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a charging furnace (Fl) of a hydrotreating or hydroconversion reaction section (R-1), and cool a reaction effluent from the hydrotreating or hydroconversion reaction section (Rl), said tubular feed-effluent heat exchanger (E-2) comprising a plurality of tubes (110) through which the reaction effluent passes, said tubes comprising an insert; - the charging furnace (Fl) configured to heat and send the preheated hydrocarbon feed-hydrogen stream mixture to the hydrotreating or hydroconversion reaction section (Rl) - the hydrotreating or hydroconversion reaction section (Rl) configured to hydrotreat or hydroconvert the hydrocarbon feedstock and produce the reaction effluent; - a first air-cooled condenser (Al) configured to cool at least part of the reaction effluent cooled by said tubular charge-effluent heat exchanger (E-2) before it is sent into a high-pressure cold separator vessel (B-2); - the high-pressure cold separator vessel (B-2) configured to separate at least a portion of the cooled reaction effluent into a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen, and - a separation column (Cl) configured to separate said first liquid effluent comprising at least a light fraction into a bottom liquid and a top effluent.

2. Installation according to claim 1, further comprising a medium-pressure cold separator vessel (B-4) configured to separate the first liquid effluent comprising at least a light fraction into a second liquid effluent comprising at least a light fraction sent to the separation column (Cl) and a second gaseous effluent comprising hydrogen.

3. Installation according to claim 2, further comprising: - a first heat exchanger (El) configured to pre-cool the entire reaction effluent (8) before sending it into said tubular charge-effluent heat exchanger (E-2); - a second heat exchanger (E-4) configured to cool the bottom liquid from the separation column (Cl), and to heat and send the second liquid effluent from the medium-pressure cold separator vessel (B-4) to the separation column (Cl) after additional heating in said first heat exchanger (El).

4. Installation according to claim 2, further comprising: - a hot high-pressure separator vessel (Bl) configured to separate the cooled reaction effluent from said tubular charge-effluent heat exchanger (E-2) into a first liquid effluent comprising at least a heavy fraction and a first gaseous effluent comprising a light fraction sent to the cold high-pressure separator vessel (B-2) after cooling in an external flow heat exchanger (E-3) and passing through said first air condenser (Al); - a medium-pressure hot separator (B-3) configured to separate the first liquid effluent comprising at least a heavy fraction into a second liquid effluent comprising at least a heavy fraction sent to the separation column (Cl), and a second gaseous effluent comprising a light fraction sent to said medium-pressure cold separator (B-4) after cooling in a second air condenser (A-2).

5. An installation according to any one of the preceding claims, wherein the tubular feed-effluent heat exchanger (E-2) is provided with a plurality of inserts fixed to the tubes of said feed-effluent heat exchanger, each insert comprising an element (100) having a rigid helical winding of a rod, preferably metallic, comprising several turns, preferably the element (100) comprising: - a sequence of several successions of a first section (S1) of length L1 comprising a rigid helical winding of a rod, preferably metallic, comprising several turns and a second section (S2) of length L2 comprising a straight rod, preferably metallic, and - a first end connected to a fixing system (200) of said element (100) to an inlet of said tube (110).

6. Installation according to claim 5, wherein the element (100) of the insert is rotationally mobile, said first end of the element (100) being attached to a mechanical link of the fixing system (200), said mechanical link allowing free rotation of said element (100) about itself around the axis (Z) of said tube (110) under the action of the reaction effluent passing through said tube (110), and said rotationally mobile element (100) having a second free end opposite said first end.

7. Installation according to claim 6, wherein the rotating movable element (100) of the insert further comprises a rotating drive piece (300) positioned between the first end of said element (100) and connected to the first section (SI) of the sequence positioned first in the sequence, said rotating drive piece comprising a shaft (3a) coaxial with the helical winding of the first section (SI) and provided with at least two blades (300b) integral with said shaft (3a).

8. Installation according to any one of claims 5 to 1, wherein the insert comprises: - a pitch pl of the helical winding of the first section SI between 10 mm and 50 mm; - a length L1 of the first section (SI) and a length L2 of the second section (S2) between 50 mm and 12000 mm; - a total insert length L| between 50% and 100% of the total length L tof the heat exchanger tube (charge-effluent), the total length of the tube L t being between 500 mm and 6000 mm.

9. A process for the hydrotreating or hydroconversion of a hydrocarbon feedstock, comprising the following steps: - preheat and send directly the hydrocarbon feed mixed with a hydrogen stream to a charging furnace by means of at least one tubular feed-effluent heat exchanger (E-2) comprising a plurality of tubes (110) through which a reaction effluent passes and comprising an insert in at least one of said tubes; - heat and send the preheated hydrocarbon feed-hydrogen stream mixture to a hydrotreating or hydroconversion reaction section (Rl) using the feed furnace (F- 1); - hydrotreat or hydroconvert the hydrocarbon feed in the hydrotreating or hydroconversion reaction section (Rl) comprising at least one reactor comprising at least one catalyst comprising at least one element selected from the elements of Group VIII of the periodic table to form the reaction effluent; - to cool the reaction effluent from the hydrotreatment or hydroconversion reaction section (Rl) by means of said tubular charge-effluent heat exchanger (E-2); - lower the temperature of at least part of the reaction effluent from the tubular charge-effluent heat exchanger (E-2) by means of a first air condenser (Al) before sending it into a high-pressure cold separator vessel (B-2); - to separate said at least a portion of the cooled reaction effluent from the first air-cooled condenser (A1) in the high-pressure cold separator vessel (B-2) to form a first liquid effluent comprising at least a light fraction and a first gaseous effluent comprising hydrogen; and - separate the first liquid effluent comprising at least a light fraction in a separation column (Cl) to form at least a bottom liquid and a top effluent.

10. Hydroconversion or hydrotreatment process according to claim 9, wherein the tubular feed-effluent heat exchanger (E-2) is provided with a plurality of inserts fixed to the tubes of said tubular feed-effluent heat exchanger, each insert comprising an element (100) comprising a rigid helical winding of a rod, preferably metallic, comprising several turns, preferably the element (100) comprising: - a sequence of several successions of a first section (S1) of length L1 comprising a rigid helical winding of a rod, preferably metallic, comprising several turns and a second section (S2) of length L2 comprising a straight rod, preferably metallic, and - a first end connected to a fixing system (200) of said element (100) to an inlet of said tube (110).

11. Hydroconversion or hydrotreating process according to claim 9 or claim 10, wherein the hydrotreating or hydroconversion of the hydrocarbon feedstock is carried out with at least one of the following operating conditions: - the temperature is between approximately 200°C and approximately 550°C; - the total pressure is between approximately 1 MPa and approximately 38 MPa; - the overall hourly spatial velocity of the liquid charge is between approximately 0.05 h 1 and about 12 hours 1 ; - the hydrogen flow comprises between approximately 50% and approximately 100% of the volume of hydrogen relative to the volume of the hydrogen flow; - the quantity of hydrogen relative to the liquid hydrocarbon charge is between approximately 50 Nm 3 / m 3 and approximately 5000 Nm 3 / m 3 .

12. Hydroconversion or hydrotreating process according to any one of claims 9 to 11, wherein the hydrocarbon feedstock comprises an initial boiling point greater than 120°C.

13. A hydroconversion or hydrotreating process according to any one of claims 9 to 12, wherein the hydrocarbon feedstock is selected from: - feedstocks of fossil origin selected from diesel fuels, vacuum distillates, atmospheric residues, vacuum residues or Fischer-Tropsch unit effluents, - feedstocks derived from biomass conversion chosen from vegetable, algal, fish, or used food oils, fats of vegetable or animal origin, or oils produced from lignocellulosic biomass, - feedstocks derived from the conversion of waste materials selected from pyrolysis oils of plastics, tires, or solid recovered fuels, - and their mixtures.

14. Hydroconversion or hydrotreating process according to any one of claims 9 to 13, wherein the high-pressure cold separator vessel (B-2) is operated at a pressure lower than the pressure of the hydrotreating or hydroconversion reaction section (Rl) and / or wherein the temperature of the high-pressure cold separator vessel (B-2) is between 20°C and 100°C.

15. A hydroconversion or hydrotreating process according to any one of claims 9 to 14, further comprising the following steps: - pre-cool the entire reaction effluent from the hydrotreatment or hydroconversion reaction section (Rl) by means of a first heat exchanger (El) before sending it to the tubular feed-effluent heat exchanger (E-2); - separate said first liquid effluent comprising at least a light fraction from the high-pressure cold separator vessel (B-2) into a medium-pressure cold separator vessel (B-4) to form a second liquid effluent comprising at least a light fraction sent to the separation column (Cl) and a second gaseous effluent comprising hydrogen; - cool the bottom liquid from the separation column (Cl) and heat and send to said separation column (Cl) said second liquid effluent comprising at least a light fraction by means of a second heat exchanger (E-4); - heat said second liquid effluent comprising at least a light fraction from second heat exchanger (E-4) before sending it to said separation column (Cl) by means of said first heat exchanger (El).

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